The air war has cost the US about $5.5 billion total since it began in August 2014. The Military Times noted that the daily cost of the war has jumped about $2 million since June.

Just last week, Dan Lamothe wrote for The Washington Post that the air war against ISIS (also known as the Islamic State, ISIL, and Daesh) is expanding "more so than most observers realize." Lamothe wrote that the Air Force dropped a record number of bombs on ISIS targets in November and December.

Many of these air strikes have been run in tandem with ground offensives carried out by local forces to reclaim territory from ISIS in Iraq and Syria. In the past year, local forces backed by US air power have reclaimed Kobane in Syria and Tikrit, Sinjar, and Ramadi in Iraq. The Kobane, Sinjar, and Ramadi operations coincided with significant upticks in US air strikes.

The US is running an aggressive air campaign in the hopes of stomping out ISIS as quickly as possible. The Obama administration has been reluctant to send in US ground troops to combat ISIS, opting to deploy forces in an advisory capacity that isn't supposed to include combat.

Lt. Gen. Charles Brown Jr., commander of US Air Forces Central Command, told the Air Force Times recently that he "hope[s] to be pretty well done with Daesh" by the end of 2016.

"That's probably aspirational, but I think we are putting pressure on Daesh," he said.